The study of light propagation in turbid media is of great interest in many medical applications. Unfortunately, in most realistic situation the analytical solution to the transport equation is not known. We show that the solution of the transport equation can be written in the form of a path integral with a quasi-particle Lagrangian. This approach extends the diffusion approximation to the case in which photons travel only a few transport mean free paths. The most probable trajectories can be described using a quasi-particle Lagrangian. The near diffusive regime is relevant to medical applications such as time dependent imaging and steady state spectral diagnosis.